Feeding mechanism for sewing-machines.



A. F. McCOLLUM. FE EDING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED IAN.5, 1915v Patented Aug. 28, 1917.

SH EE 1' l 4 SHEETS- A. F. McCOLLUM.

moms MECHANISM FOR SEW'ING MACHlNES.

APFUCATION FILED JAN. 5, .915.

Patented Aug. 28, 1917.

4 SHEETS-SHEET 2.

,EML v A. F. IVIcCOLLUM. FEEDING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED IAN.5. I9I5. I

Patented Aug. 28, 1917.

4 SHEETS-SHEEI 3.

A. F. MCCOLLUM.

FEEDING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JAN-5.1915.

Patented Aug. 28'

4 SHEETS-SHEET 4.

TINT %ATE% AEN @TQ,

ALFRED F. MGCOLLUM, OF BLOOMSBURG, PENNSYLVANIA, ASSIGNOR OF THREE-FIFTHS TO JAMES MAGEE, 21), OF BLOOMSBURG, PENNSYLVANIA.

FEEDING MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented Aug. 28, 1917..

Application fi1ed January 5, 1915. Serial No. 604.

To all whom it may concern:

Be it known that I, ALFRED F. MoCoLLUM, a citizen of the United States, residing in Bloomsburg, Pennsylvania, have invented certain Improvements in Feeding Mechanism for Sewing-Machines, of which the following is a specification.

My invention consists of improvements in feeding mechanism for sewing machines and is particularly designed for sewing thick and hard fabrics such as carpets, rugs, oil cloth, etc.

It has heretofore been impossible, with machines known to the market, to insure a positive and even feeding of fabrics such as those noted especially if they have prtions of different thickness or are otherwise irregular and one object of my invention is to provide a machine which shall be capable of successively sewing these fabrics. Another object of the invention is to provide mechanism capable of evenly and positively feeding fabrics such as those specified without injury thereto.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had to the accompanying drawings, in which,

Figures 1 and 2 are end elevations, partly in section, of a sewing machine including my invention and showing certain of the elements in diiferentoperative positions;

Fig. 3 is a vertical section taken on the line aa Fig. l; and

Fig. i is a side elevation 011 a slightly reduced scale, showing the several parts in the positions illustrated in F ig. 1.

In the above drawings, 1 is a sewing machine head which may be of any suitable type and in the present instancehas a main driving shaft 2 rotated by a pulley 3 or hand wheel 4 in the usual manner. On the outer end of this shaft is fixed a disk 5 having a crank arm 6 provided with a pin 7 eccentric to the axis of said shaft 2 (see Figs. 1 and 2). This pin 7 is arnnged to operate within a slot 8 in one arm of a lever 9 pivoted at 10 to a sleeve 11 which is fixed to a slidably guided bar 12 and is also slidable on a presser foot bar 13. The other arm 1 1 of the lever 9 is slotted at 15 to provide a bearing for a pivot pin 16 which projects from the upper end of a link 17 and the lower end of the latter is pivotally connected to a collar 18 foot bar 13.

A coil spring 19 on the presser foot bar tends to depress the sleeve 11 and an adjusting screw 20 threaded into the head of the machine serves as a means for varying the intensity with which the spring presses upon said sleeve. The lower end of the latter, under certain operative conditions, abuts upon the shoulder provided by the hooked lower end 22 of a vertically slidable lever 21, which also has a projection 23 coacting with a cam head 221 on a lifter lever 25 whereby the presser foot bar 13 and presser foot may be manually raised.

Any suitable form of stitch-forming mechanism may be used and as shown in the drawings this consists of a needle bar 2"? vertically reciproca'ble within the head 1 by means of a connecting rod 28 pivotally connected to the crank arm 6. The bobbin mechanism which cooperates with the needle has been omitted in the drawings for sake of clearness.

The fabric feeding mechanism consists of a crankshaft 29 mounted below the bed plate 30 and receives a rocking motion through a link 31 actuated from the main shaft 2. This crank shaft 29 has fixed to it an arm 32 which forms the actuating means for a lower fabric feed plate 33 having a toothed portion operative within a slot 35 in the bed plate 30.

My invention includes feeding mechanism which operates on the upper surface of the fabric at the same time that the lower fabric feed plate operates on its lower surface. This upper feeding mechanism consists of a shaft 36 rota-tably supported above the up per surface of the bed plate 30 in bearings 37 secured thereto and has fixed to it an arm 38 connected through a link 39 with the crank shaft 29, so that a movement of the latter will impart a similar movement to the shaft 36.

Extending upwardly from the shaft 36 is an arm 11 having a longitudinal slot 42 for the reception of a bolt 17 whereby said arm is connected to one end of a link 46 whose opposite end is pivoted to an upper feed bar 13. This latter is pivoted at 4A to the vertically movable bar 12 and its lower end or foot 415 is toothed for engagement with the upper portion of the fabric operated on.

fixed to the presser ing of any of the pivotal connections of the' feed mechanism, a tension coil spring 48 has one end connected to a'fixed projection 49 on the machine head and has its other end connected to .an arm 50 on the shaft 36.

For raising and lowering the feed plate the fabric and the bar 12 will again be raised to turn the lever eon the'pin' 16 as a pivot to cause lifting of the upper feed bar 43. At the same time the shafts 29 and 36 will be rocked in a direction opposite to that hitherto noted and the feeding bars will be returned to the positions shown in Fig. 1.

33 I provide it With a forked extension b e f From the above description it will be tween whose branches extends a pin projecting from an arm 51 fixed to a shaft 52.. This shaft receives a rocking motion by mechanism forming no part of this invention.

The rock shaft 36 has rotatably mounted upon it a suitable number of wheels or rollers 54 so placed as to engage the upper surface of the fabric and-thereby hold it in contact with the work plate or bed of the machine without retarding its free movement.

Under operating conditions the fabric rests on the upper surface X, of the table or platform and when the shaft 2 is turned it oscillates the lever 9 on the pin 16 as a pivot thereby lowering the bar 12 through the pin 10 and sleeve 11, and causing the upper fabric feed bar 43 to be lowered. Simultaneously with this action the link 31 will be moved to rock the shaft 29 and hence the shaft 36 thereby swinging the upper feed bar 43 in the direction of the arrow 9 Fig. 1) through the medium of the crank arm 41 and link 46. This movement of the shaft 29 will also move the arm 32 and the feed plate 33 in the same direction, the latter being also elevated by means of thearm 51. on the shaft 52. The upper feed bar 43 thus receives a downward movementinto engagement with the fabric and thereafter has a forward movement which will be simultaneous with the upward and forward movement of the feed plate 33. The fabric is therefore firmly gripped by the toothed portions of the upper and lower feed members and carried forward with a positive move ment.

After the bar 12 has completed its downward movement the sleeve 11 engages and is stopped by the shoulder 22 so that the continued movement of the pin 7 as the shaft 2 is turned rocks the lever 9 on the pin 10 as a center thereby raising the arm 14 and lifting the presser foot. This motion is so timed as to occur while the feeding bars 33 and 45 are carrying the fabric forwardly and the presser foot remains in its raised position until these bars have reached their extreme forward positions. The arm 14 of the lever 9 will then be lowered to bring the presser foot 26 into contact with Copies of this patent may be obtained for five cents each by addressing the noted that the toothed feeding members clamp and move the fabric and the presser foot acts to hold said fabric in position after it has been released by thefeeding members.

\Vhile my invention has been described in connection with sewing machines for fabrics it is also serviceable andmay be used to great advantage for sewing other heavy or tough materials such as leather, furs, cardboard, etc.

I claim l. The combination in. a sewing machine of stitch-forming mechanism; a bed plate for supporting a fabric; a feeding member placed to engage the under face of the fabric; means for operating said feeding member; a supporting structure; a bar slidably mounted in said supportingstructure; means for reciprocating said bar; a second feeding member mounted to engage the upper face of the fabric and pivotally connected to said bar; a shaft having a crank.

arm; a link connecting said crank arm with said latter feeding member; means connecting theshaft with said operating means; an arm on said shaft; and a spring connecting said arm with the supporting structure.

2. The combination in a sewing machine of stitch forming mechanism; a bed plate for. supporting the fabric; a feeding member placed to engage the under face of the fabric;.means for operating said feeding member; a head; a bar slidably mounted in said head; means for reciprocating said bar; a second feeding member mounted to engage the upper face of the fabric and pivotally connected to the bar; a shaft mounted in bearings above the top surface of the bed plate; two arms for said shaft;

a link connecting one ofsaid'arm's'to the second feeding member; a spring extending between the second arm and a portion of the head; with means for actuating the shaft and the first feeding member. 7

In testimony whereof, I have signedmy name to this specification, in the presence of two subscribing witnesses. 1

ALFRED F. MGCOLLUM.

Commissioner of Patents.

Washington, D. C. 

